How to count the days between two dates
- Choose the start date and the end date. The Today buttons fill in the current date.
- Tick Include the end date if both days must count.
- Read the number of days. The result updates as you change a date.
If the end date is before the start date, the tool swaps them and tells you, so you always get a positive count.
Include the end date or not
The difference between 1 January and 2 January is 1 day. If you count both days, it is 2. Which one you need depends on what you are counting:
- Exclude the end date when you count nights or elapsed time: a hotel stay from the 1st to the 5th is 4 nights, and a loan from the 1st to the 31st runs 30 days.
- Include the end date when you count each calendar day: 5 days of leave from the 1st to the 5th, or the number of days a project is active.
What the result shows
- The total number of days, and the same period as weeks and days.
- The period as years, months and days. See date difference for how that is worked out.
- The number of weekdays, Monday to Friday. For holidays and other weekends, use the business days calculator.
- Weeks, months, years, hours, minutes and seconds as decimals.
How the calculation works
Each date is turned into a whole day number, and the answer is the difference between the two numbers. Leap days are included, so a period that crosses 29 February is one day longer. Time zones and daylight saving time do not matter, because no clock times are used.
A year has 365 days, or 366 in a leap year. A leap year is a year divisible by 4, except for century years, which must be divisible by 400. So 2024 and 2000 are leap years, and 2100 is not.
Add or subtract days
Type a number of days in Add or subtract days to find the date that many days after the start date. Use a negative number to go back. This answers questions such as what date is 90 days from today.
Related calculators
Use days until to count down to an event and days since to count up from one. For other units, see weeks between dates and months between dates, or the working days calculator. To convert dates to and from Unix time, use the date to timestamp converter. Formulas for Excel, SQL and code are in the guide to days between dates.